As shown in FIG. 9, there has been known such an electric current detector in which a core (7) having a magnetic gap G and a printed circuit board (4) to which a Hall element (41) is attached are accommodated in an outer case (6), the Hall element (41) being interposed in the magnetic gap G of the core (7).
When an electric current passes through the hollow portion of the core (7), the magnitude of the electric current is detected by the Hall element (41).
Typically, the electric current detector in which the outer case is previously resin molded is adopted. After the core is accommodated in a core accommodating chamber formed in the outer case, a synthetic resin (e.g., an epoxy resin) is filled into the core accommodating chamber to fix the core into the outer case (see Patent Document 1).
In the assembling process of the electric current detector in which the synthetic resin is filled into the outer case, first, the core is accommodated in the core accommodating chamber in the outer case to temporarily fix the core into the outer case, and the synthetic resin is filled into the outer case to fix the core into the outer case, thereby performing electric insulation with respect to the core.
In this connection, in the electric current detector, the Hall element is required to be precisely positioned in the magnetic gap of the core.
However, in the electric current detector in which the synthetic resin is filled into the outer case, a large space (clearance) is necessary for filling the synthetic resin into the outer case, resulting in increase in size of the outer case. In addition, to ensure positioning accuracy for temporarily fixing the core into the outer case, a complicated configuration for forming a positioning projection on the inner surface of the case, or the like is necessary. The positioning operation of the core is troublesome.